libpthread/nptl/sem_init.c

   1 /* Copyright (C) 2002, 2007 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <semaphore.h>
  21 #include <lowlevellock.h>
  22 #include "semaphoreP.h"
  23 #include <bits/kernel-features.h>
  24
  25
  26 int
  27 sem_init (
  28      sem_t *sem,
  29      int pshared,
  30      unsigned int value)
  31 {
  32   /* Parameter sanity check.  */
  33   if (__builtin_expect (value > SEM_VALUE_MAX, 0))
  34     {
  35       __set_errno (EINVAL);
  36       return -1;
  37     }
  38
  39   /* Map to the internal type.  */
  40   struct new_sem *isem = (struct new_sem *) sem;
  41
  42   /* Use the values the user provided.  */
  43   isem->value = value;
  44 #ifdef __ASSUME_PRIVATE_FUTEX
  45   isem->private = pshared ? 0 : FUTEX_PRIVATE_FLAG;
  46 #else
  47   isem->private = pshared ? 0 : THREAD_GETMEM (THREAD_SELF,
  48                                                header.private_futex);
  49 #endif
  50
  51   isem->nwaiters = 0;
  52
  53   return 0;
  54 }